Debit order mess up

I missed a payment for the first time in my 6 years that I've been with them since then they've been going into my account as they please since, payment missed was for 20th of Feb and no one phoned me, then they debited again on the 15th of March R1066.62 , when they were suppossed to debit on the 20th they didn't debit so the next day I tried calling them to ask why was the account not debited I could not go through however I got a whatsapp link to use as a self service and did follow the steps and used Bill payment option where I use my card and made payment, I then phoned them got through to an agent that told me that she can see the payment but it not cleared however the debit order will not run but no guess what?? they came back and debited my account on 24th of March till this day that payment is still not cleared as a result my outgoing calls line is suspended and they debited again on the 31st of March mind you I'm using a cheque account and they now messing up my score, I phoned in and an agent told me to email statement and I have not received any response, I can assure you one thing in this experience that I will never ever take your contract or refer any of my friends and family to this ****ty Service Provider. can someone sort this mess